Method and system for externally treating the blood

Abstract

A method and system are disclosed for externally treating human blood, with the objective of reducing the functioning lymphocyte population in the blood system of a human subject. According to the method, blood is withdrawn from the subject and passed through an ultraviolet radiation field in the presence of from about 1 nanogram to 100 micrograms per ml of blood, of a dissolved photoactive agent capable of forming photo-adducts with lymphocytic-DNA, mobile hormonal receptors or antigen sites to thereby effect covalent bonding between the photoactive agent and the same, thereby inhibiting the metabolic processes of the lymphocytes or complexing them; and thereupon returning the irradiated blood to the subject. The withdrawn blood may be formed into an extracorporeal stream and flowed through a treatment station whereat the irradiation is effected, as for example by exposure to UV radiation; and such flow process may be conducted on a continuous basis. If desired, at least portions of the treated blood may then be separated, as for example, by a continuous centrifuge, before returning the remaining diverted blood to the subject.

What is claimed is: 
     
       1. A method for reducing the functioning population of a blood constituent in the blood supply of a human subject, comprising the steps of: withdrawing blood from said subject, and irradiating said withdrawn blood with UV radiation in the presence of an effective amount of a dissolved photoactive chemical agent specific for a receptor site in or on the blood constituent and capable when activated by said UV radiation of forming photo-adducts with blood constituent receptor sites, to thereby effect chemical bonding between said photoactivated chemical agent and said receptor sites, thereby initiating the destruction and/or removal of said blood constituent from the blood supply of the subject and returning the irradiated blood to said subject.   
     
     
       2. The method according to claim 1 wherein the blood constituent comprises activated T-lymphocytes. 
     
     
       3. The method according to claim 1 wherein the photoactivated chemical agent comprises a polypeptide selected from the group consisting of insulin, interleukin, thymopoietin and transferrin, and wherein said agent further comprises a photocytotoxic chemical agent covalently-linked to said polypeptide. 
     
     
       4. The method according to claim 1 wherein the photoactivated chemical agent comprises a liposome, said liposome having an antibody or a polypeptide capable of binding to said constituent receptor site covalently linked to its outer surface, and said liposome internally incorporating an effective amount of a photocytotoxic agent therein. 
     
     
       5. The method according to claim 4 wherein the polypeptide is selected from the group consisting of insulin, interleukin, thymopoietin and transferrin. 
     
     
       6. The method according to claim 4 wherein said antibody is a monoclonal antibody and said liposome is from about 500 angstroms to about 0.5 micrometers in diameter. 
     
     
       7. The method according to claims 3 or 4 wherein the photocytotoxic chemical agent comprises a moiety selected from the group consisting of psoralen, pyrene cholesteryloleate, acridine, porphyrin, fluorescein, rhodamine, 16-diazocortisone, ethidium, transition metal complexes of bleomycin, transition metal complexes of deglycobleomycin and organoplatinum complexes. 
     
     
       8. The method according to claims 3 or 4 wherein the covalent linkage comprises a disulfide moiety. 
     
     
       9. The method according to claim 4 further comprising the step of separating at least portions of said photoactivated chemical agent-blood constituent complex by dialysis, before returning said blood to said subject.